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本文出自【DylanAndroid的博客】
【玩转sqlite系列】(六)sqlite数据库应用案例实现历史搜索记录
前面通过一系列的文章讲述了sqlite的各种使用场景，那么我们用一个实际的案例去实现一个搜索历史记录的功能。
这里面用到了以下内容：【Android自定义View实战】之自定义超简单SearchView搜索框
Android宽度全屏的Dialog和DialogFragment用法
Java泛型应用之打造Android万能ViewHolder-超简洁写法
Java泛型应用之打造Android中ListView和GridView万能适配器【CommonAdapter】–超简洁写法
不了解的可以去学习一下。
一.编写一个历史搜索记录实例对象
package cn.bluemobi.dylan.sqlite;
import java.util.Date;
/** * 搜索记录的操作对象 * Created by Administrator on 2016-11-20. */
public class History {
/** * id 主键，自增 */
private int id;
/** * 搜索的内容 */
private String content;
/** * 搜索的时间 */
private String time;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
public String getTime() {
return time;
}
public void setTime(String time) {
this.time = time;
}
}
二.编写一个操作数据库的管理工具类
package cn.bluemobi.dylan.sqlite;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.sqliteDatabase;
import android.os.Environment;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
/** * 数据库操作管理类 * Created by Administrator on 2016-11-19. */
public class DBManager {
private static volatile DBManager dbManager;
private sqliteDatabase sqliteDatabase;
private DBManager() {
openDataBase();
createTable();
}
public static DBManager getDBManager() {
if (dbManager == null) {
synchronized (DBManager.class) {
if (dbManager == null) {
dbManager = new DBManager();
}
}
}
return dbManager;
}
/** * 数据库名称 */
private final String DATABASE_NAME = "info.db";
/** * 表名 */
private final String TABLE_NAME = "history";
/** * 表格所包含的字段 */
private class HistoryDbColumn {
/** * 字段一 id */
public static final String ID = "id";
/** * 字段二 内容 */
public static final String CONTENT = "name";
/** * 字段三 时间 */
public static final String TIME = "time";
}
/** * 1.创建或打开数据库连接 **/
private void openDataBase() {
File dataBaseFile = new File(Environment.getExternalStorageDirectory() + "/sqlite",DATABASE_NAME);
if (!dataBaseFile.getParentFile().exists()) {
dataBaseFile.mkdirs();
}
sqliteDatabase = sqliteDatabase.openOrCreateDatabase(dataBaseFile,null);
}
/**** * 2.创建表 */
private void createTable() {
String sql = "CREATE TABLE " +
"IF NOT EXISTS " +
TABLE_NAME + "(" +
HistoryDbColumn.ID + " Integer PRIMARY KEY AUTOINCREMENT," +
HistoryDbColumn.CONTENT + " varchar," +
HistoryDbColumn.TIME + " datetime)";
sqliteDatabase.execsql(sql);
}
/** * 插入一条数据 * * @param history * @return */
public long insert(History history) {
ContentValues contentValues = new ContentValues();
contentValues.put(HistoryDbColumn.CONTENT,history.getContent());
contentValues.put(HistoryDbColumn.TIME,history.getTime());
long num = sqliteDatabase.insert(TABLE_NAME,null,contentValues);
return num;
}
/** * 根据id删除一条数据 * * @param id * @return */
public long delete(int id) {
long num = sqliteDatabase.delete(TABLE_NAME,HistoryDbColumn.ID + "=?",new String[]{String.valueOf(id)});
return num;
}
/** * 根据id修改一条数据 * * @param id * @return */
public long update(History history,int id) {
ContentValues contentValues = new ContentValues();
contentValues.put(HistoryDbColumn.CONTENT,history.getTime());
long num = sqliteDatabase.update(TABLE_NAME,contentValues,new String[]{String.valueOf(id)});
return num;
}
/** * 根据id查询一条数据 * * @param id * @return */
public History qurey(int id) {
History history = null;
Cursor cursor = sqliteDatabase.query(TABLE_NAME,new String[]{String.valueOf(id)},null);
if (cursor != null) {
if (cursor.moveToNext()) {
history = new History();
history.setId(cursor.getInt(cursor.getColumnIndex(HistoryDbColumn.ID)));
history.setContent(cursor.getString(cursor.getColumnIndex(HistoryDbColumn.CONTENT)));
history.setTime(cursor.getString(cursor.getColumnIndex(HistoryDbColumn.TIME)));
}
}
return history;
}
/** * 根据id查询一条数据 * 倒序 * * @return */
public List<History> queryAll() {
List<History> historys = new ArrayList<>();
Cursor cursor = sqliteDatabase.query(TABLE_NAME,HistoryDbColumn.TIME + " desc");
if (cursor != null) {
while (cursor.moveToNext()) {
History history = new History();
history.setId(cursor.getInt(cursor.getColumnIndex(HistoryDbColumn.ID)));
history.setContent(cursor.getString(cursor.getColumnIndex(HistoryDbColumn.CONTENT)));
history.setTime(cursor.getString(cursor.getColumnIndex(HistoryDbColumn.TIME)));
historys.add(history);
}
}
return historys;
}
/** * 根据内容查询一条数据 * * @return */
public History queryByContent(String content) {
History history = null;
Cursor cursor = sqliteDatabase.query(TABLE_NAME,HistoryDbColumn.CONTENT + "=?",new String[]{content},null);
if (cursor != null) {
if (cursor.moveToNext()) {
history = new History();
history.setId(cursor.getInt(cursor.getColumnIndex(HistoryDbColumn.ID)));
history.setContent(cursor.getString(cursor.getColumnIndex(HistoryDbColumn.CONTENT)));
history.setTime(cursor.getString(cursor.getColumnIndex(HistoryDbColumn.TIME)));
}
}
return history;
}
}
三.搜索对话框的布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:minHeight="250dp" android:orientation="vertical">
<cn.bluemobi.dylan.sqlite.SearchView android:id="@+id/sv" android:padding="10dp" android:background="@color/colorPrimaryDark" android:layout_width="match_parent" android:layout_height="wrap_content">
</cn.bluemobi.dylan.sqlite.SearchView>
<ListView android:id="@+id/lv" android:layout_width="match_parent" android:layout_height="match_parent"></ListView>
<TextView android:id="@+id/tv" android:layout_gravity="center" android:gravity="center" android:layout_weight="1" android:layout_width="match_parent" android:layout_height="match_parent" android:text="暂无搜索记录" />
</LinearLayout>
四.编写功能代码
package cn.bluemobi.dylan.sqlite;
import android.app.Dialog;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.Date;
import java.util.List;
import cn.bluemobi.dylan.sqlite.adapter.CommonAdapter;
import cn.bluemobi.dylan.sqlite.adapter.CommonViewHolder;
/** * sqlite应用案例实现搜索记录 * Created by Administrator on 2016-11-20. */
public class SearchActivity extends AppCompatActivity implements View.OnClickListener {
private EditText et;
private ListView lv;
private TextView tv;
private Dialog dialog;
private SearchView sv;
private Button bt;
private List<History> histories;
private CommonAdapter<History> commonAdapter;
private final int MAX_ITME = 5;
private void assignViews() {
et = (EditText) findViewById(R.id.et);
}
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().setTitle("sqlite应用案例实现搜索记录");
setContentView(R.layout.ac_search);
assignViews();
intiDialog();
addListener();
initData();
}
/** * 添加按钮监听 */
private void addListener() {
et.setOnClickListener(this);
}
/*** * 初始化搜索对话框 */
private void intiDialog() {
dialog = new Dialog(this,R.style.Dialog_FullScreen);
dialog.setContentView(R.layout.dialog_search);
dialog.getWindow().setGravity(Gravity.TOP);
dialog.setCanceledOnTouchOutside(true);
dialog.setCancelable(true);
WindowManager.LayoutParams lp = dialog.getWindow().getAttributes();
lp.width = WindowManager.LayoutParams.MATCH_PARENT;
lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
dialog.getWindow().setAttributes(lp);
lv = (ListView) dialog.findViewById(R.id.lv);
tv = (TextView) dialog.findViewById(R.id.tv);
sv = (SearchView) dialog.findViewById(R.id.sv);
bt = (Button) dialog.findViewById(R.id.bt);
bt.setOnClickListener(this);
lv.setEmptyView(tv);
}
/** * 初始化数据 */
private void initData() {
commonAdapter = new CommonAdapter<History>(this,histories,R.layout.item_for_search) {
@Override
protected void convertView(CommonViewHolder commonViewHolder,History history) {
TextView tv = commonViewHolder.get(R.id.textView);
tv.setText(history.getContent());
}
};
lv.setAdapter(commonAdapter);
notifyAdapter();
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.et:
if (!dialog.isShowing()) {
dialog.show();
}
break;
case R.id.bt:
addHistory();
break;
}
}
/** * 点击搜索按钮新增一条记录 */
private void addHistory() {
String inputText = sv.getInputText();
if (inputText.isEmpty()) {
Toast.makeText(this,"请输入内容进行搜索",Toast.LENGTH_SHORT).show();
return;
}
/**1.先判断数据库当中有没有这条历史记录，如果有则修改其搜索的时间即可*/
History history = DBManager.getDBManager().queryByContent(inputText);
if (history != null) {
history.setTime(new Date().toString());
DBManager.getDBManager().update(history,history.getId());
} else {
/**2.判断搜索记录是否达到限值,达到极限则删除一条数据**/
if (histories != null && histories.size() == MAX_ITME) {
DBManager.getDBManager().delete(histories.get(histories.size() - 1).getId());
}
/**3.插入一条数据**/
history = new History();
history.setContent(sv.getInputText());
history.setTime(new Date().toString());
long num = DBManager.getDBManager().insert(history);
if (num != -1) {
Log.d(Contacts.TAG,"插入成功");
} else {
Log.d(Contacts.TAG,"插入失败");
}
}
notifyAdapter();
}
/** * 更新数据库当中的数据 */
private void notifyAdapter() {
histories = DBManager.getDBManager().queryAll();
commonAdapter.notifyDataSetChanged(histories);
}
}
